Significance Infection with simian type D retrovirus (SRV/D) is endemic in many populationsof macaques. SRV/D is a significant pathogen in macaque colonies, being the etiologic agent of one form of simain acquired immune deficiency disease. In addition to its importance from an animal health perspective, SRV/D infection may also represent a significant confounding variable in the interpretation of research results obtained using macaques as experimental subjects. In recognition of the importance of establishing and maintaining breeding colonies of macaques free of SRV/D infection. Objective The objectives of this research are to develop enhanced serologic and virologic diagnostic tests for SRV/D infection and employ these improved assays in support of the NCRR-sponsored SPF rhesus macaque development program, and other independent efforts to eliminate SRV infection in macaques used in biomedical research. Results We have successfully developed and validated a nested RT-PCR for the detection of SRV RNA in macaque plasma, and other cell-free media. Additionally, we have developed and validated nested-PCR protocols for use with pooled peripheral blood samples from macaques. We have consistently detected a single positive sample pooled with up to 5 negative samples. While not appropriate for all screening situations, under specific circumstances pooled sample screening can greatly increase the cost-efficiency of PCR testing. This would be especially useful and cost-effective in validating the continued SRV-negative status of established SPF colonies. Future Directions We will continue to evaluate the limits and utility of pooled sample tesing of macaque blood to determine the optimal pool size. In addition, we have begun preliminary development of a DNA vaccine against SRV. Such a vaccine would be relatively inexpensive to produce and if effective, could theoretically eliminate viral transmission in highly endemic populations, where test and removal procedures are not feasible. KEYWORDS SRV/D, retrovirus, macaque, diagnosis, PCR, SPF